Balancing The MCR With Moment Lens And Filter

Discussion in 'Movi Technical' started by Pavel Houda, Jan 30, 2019.

  1. Pavel Houda

    Pavel Houda Member

    Joined:
    Jan 15, 2019
    Messages:
    59
    Likes Received:
    25
    I just got the Moment Wide with the Moment Case on iPhone Xs Max, on the MCR, and I really had no problem balancing the rig but the MCR servos sometimes struggled struggled when tilted towards the extremes in the Custom Tuned Mode. If I re-tuned the servos, they worked sometimes, struggled other times. They seemed at the edge of their torque. They had always enough torque in the Plus mode (I am guessing at that point they are the least smooth). Trouble came when I added the 62mm filter adapter and an ND filter. These aren't very heavy, but they are away from the center of gravity, so the moment of inertia is significant enough. I couldn't balance the MCR with the weights supplied. I had to use all three counterweights for the tilt/roll, nothing left for the pan axis. I know that there is an add-on kit, but I don't have it, plus it costs too much for what it is. So I improvised using couple of M3 screws and some weighty washers I found around the house. It works ok, but eventually I will find something more elegant. I still don't feel like spending $40 fo a pair of the smallest counter-weights. Anyway, the servo-motors still struggle at extreme tilt positions in the "Tuned" balancing mode, but work ok in the "Plus" mode. IMG_0245.jpeg IMG_0245.jpeg IMG_0244.jpeg View attachment 12433 . My semipermanent solution will involve a stack of washers from this kit:https://www.amazon.com/gp/product/B07KQT4PKW/ref=ppx_yo_dt_b_asin_title_o00__o00_s00?ie=UTF8&psc=1
     

    Attached Files:

    #1 Pavel Houda, Jan 30, 2019
    Last edited: Jan 31, 2019
    Akin Oshoko and Marc Smith like this.
  2. Pavel Houda

    Pavel Houda Member

    Joined:
    Jan 15, 2019
    Messages:
    59
    Likes Received:
    25
    Actually, I am glad that I had to use the washers as counterweights on the pan axis, because the small MCR counterweights in the kit are too light to do a good job balancing. The small kit counterweights are about 20g each. In order to do a real balance, I needed 2 x 47g. I know that some will think that it's not so critical, but IMHO, the better the balance, the less the servo has to work, the longer the batteries will last and the smoother the motion will be. The servos ideally only deal with kinetic disturbances, not with static balancing. On the pan arm, there is no leveraging like the other axes, so the only way to do a balance is by controlling the mass. The washers give me a little freedom to tweak the mass, unlike using the small counterweight from the kit where the mass is fixed (and too small to do the job).
     
  3. Dave Johns

    Dave Johns New Member

    Joined:
    Jul 17, 2018
    Messages:
    22
    Likes Received:
    14
    A fine art indeed. I have the iPhone X and enjoy shooting with the anamorphic lens plus filters (from Moment). The most frustrating part of the MCR is the difficulty in various lens/filter arrangements while out and about; not really convenient while in a busy museum to change shooting style and having to go through a balancing act. The only thing I can think of is to buy another counterweight kit to have for different setups and change out quicker.

    I watched FF video a few times to get a better idea of how to balance and how the physics of the MCR works.
     
  4. Pavel Houda

    Pavel Houda Member

    Joined:
    Jan 15, 2019
    Messages:
    59
    Likes Received:
    25
    Little re-balancing is fairly easy. If it is really little, one can get away with little cheating and use the "Plus" setting on the servos and not rebalancing. {Actually with the extra weights, I can only get the MCR running in the "plus" Tuning setting. "Custom" suffers no matter how much I try to run the "Custom Tuning"}. Big change is hard. I think that the weight difference between the Moment Wide and Moment Tele isn't so bad, but the Anamorphic is much lighter, so I had to remove the two lowest counterweights, but I did get away with leaving the the pan axis counterweight alone.
    The filters are messing things up because of the high momentum of inertia due to the distance from the axis(COG), but in my case it sure messed things up so bad, the counterbalance ran out of adjustment range and I had to add weights. Maybe little better on the iPhone X than on the iPhone Xs Max since the phone is little smaller. Best to leave the filters on any lens, and use at least the ND filter for its weight. It is probably a good idea anyway.
    Moving the add-on lens from the iPhone Normal to Tele position really messes things up.
    Adding Power cable, Mic cable (or both) makes the thing basically unbalanceable, but the servos can probably handle it.
    That whole arrangement is clumsy, messy and heavy once you add anything to the phone.
    There is certainly a room for invention.
     
    #4 Pavel Houda, Feb 20, 2019
    Last edited: Feb 20, 2019
  5. Dave Johns

    Dave Johns New Member

    Joined:
    Jul 17, 2018
    Messages:
    22
    Likes Received:
    14
    @Pavel Houda That about sums it up. I just have to plan how I really want to shoot before heading out. It is a great little device, but I have very mixed feelings about the investment I made. Movi app is for another thread and another day.
     
    Pavel Houda likes this.
  6. Pavel Houda

    Pavel Houda Member

    Joined:
    Jan 15, 2019
    Messages:
    59
    Likes Received:
    25
    IMHO, they need to make more room around the actual gimbal. This arrangement with the grip to the side is cute and different, but impractical. Those counterweights constantly bump my fingers.
    Adding additional weights is counterproductive with mobile devices. I feel that those counterweights make it almost as heavy as DSLR. The weight and convenience are the key advantages of phones over heavy and clumsy rigs. They need to add threaded adjustments to move around the center of gravity like Steadicams and Glidecams do it, so that they can achieve balance without increasing the weight of the rig.
    The actual gimbal, servos and functionality are the best I ever tried, even with the lack of object tracking. If Filmic supported it, that would be also great, even though I don't know how they could integrate that with the Freefly software features. That would require more integration than just some API to the mechanics and controls.
    I may just use it without add on lenses or with just one lens setup, and shoot with other attachment combinations out of hand, on tripod or whatever else I can think of.
     
    #6 Pavel Houda, Feb 20, 2019
    Last edited: Feb 20, 2019
  7. Dave Johns

    Dave Johns New Member

    Joined:
    Jul 17, 2018
    Messages:
    22
    Likes Received:
    14
     
    Pavel Houda likes this.
  8. viktor manshtein

    viktor manshtein New Member

    Joined:
    Feb 1, 2019
    Messages:
    25
    Likes Received:
    11
    I easily managed to make balancing using only a standard set of loads IMG_0480.jpg IMG_0482.jpg IMG_0484.jpg
     
  9. viktor manshtein

    viktor manshtein New Member

    Joined:
    Feb 1, 2019
    Messages:
    25
    Likes Received:
    11
    i use iphone xs max
    but there is still no filter in the system, it has not yet been delivered.
    I liked the anamorphic lens more than the wide one.
    the more he comes under two lenses iPhone
     
  10. Simon Hughes

    Simon Hughes Member

    Joined:
    Jul 13, 2018
    Messages:
    45
    Likes Received:
    19
    I have to say that I'm amazed looking at those photos that you seem to have much more weight (both top and bottom) toward the front... I would have thought the top weight would need to be further toward the rear. (Based on balancing my 8+ with Moment Wide and filter array.)

    Also wonder why your phone is not immediately abutting the weight clamp.
     
    Pavel Houda likes this.
  11. viktor manshtein

    viktor manshtein New Member

    Joined:
    Feb 1, 2019
    Messages:
    25
    Likes Received:
    11
    While this is a preliminary setting, since
    I do not have the ND filter yet, it is delayed by the mail, as I receive it, I will do a more accurate balancing. I acquired filters from Breakthrough, as they are very high quality and at the same time very light, and I hope it will be easy to balance the system with them.
     
  12. Demetri Zuev

    Demetri Zuev New Member

    Joined:
    Aug 29, 2018
    Messages:
    4
    Likes Received:
    1
    I'm using a Xs Max with a Moment wide, a filter mount and a ND. Having two sets of counterweights I still can't balance the thing properly. The only thing I manage to balance is the "left-to-right", everything else does not hold position when with Movi disabled, no matter what I do, the slightest bump makes it trip forward or towards me. When operational motors do compensate and hold the phone steady, but that's not right, as it should be perfectly balanced with the motors off from the beginning. Very frustrated, thought that a second counterweight kit will solve the problem but I can't figure it out.

    P.S.: My initial plan to use a Black Pro-Mist and an ND on top of it is crumbling fast...(
     
  13. Pavel Houda

    Pavel Houda Member

    Joined:
    Jan 15, 2019
    Messages:
    59
    Likes Received:
    25
    00000IMG_00000_BURST20190303141402_COVER.jpg 00000IMG_00000_BURST20190303141402_COVER.jpg IMG_20190303_141435.jpg Properly statically balanced system should allow you to set the phone into just about any direction and it should stay there, but shouldn't stay in that position if you bump it. In that case, it will and should move freely, since the servos are powered down and have minuscule friction. If I understand your comment, the tilt is not holding, but falling towards you. In that case move the side counterweights away from you (to the lens side). If you get too far and the phone starts rolling away from you, back the two counterweights towards you, till it holds in just about any tilt position (balance), but NOT if you bump it. Don't forget to also balance the phone while you point the lens towards the ground. In that case, a the phone should stay balanced horizontally, as well as in just about any position you put it in pointing downwards. If it cannot hold tilt, balance the two counterweight arms on the side, so that they balance around the horizontal axis. If that holds, but the phone leans left or right, and you cannot fix it with the main counterweights, then you may need to add extra weight on the pan arm. Generally you can either balance adding weight or moving the same weight away from the axis of rotation (its really the moment of inertia you try to balance), but the way the pan counterweight is designed, the distance is fixed, so you can only add mass/ 00000IMG_00000_BURST20190303141402_COVER.jpg 00000IMG_00000_BURST20190303141402_COVER.jpg weight.

    I have quite bit of counterweight on the gimbal. On top of the iPhone Xs Max with the Moment case and Moment wide, I have fairly heavy B+W brass filter on it (22.9g). I also use Tiffen polarizing filter which is even heavier (24.7g). I have no idea how heavy the Pro-Mist is, but I doubt that it is much heavier than the circular polarizer. If I were to guess, the two filters on top of one another would cause vignetting with the Moment wide, unless you go with larger diameter filters. I never tried it, but Moment is selling 72mm variable ND filter with step-up ring, so larger filters should work. More counterweights yet though, but I have no doubt that you should be able to balance it, and that the servos will handle it. I had to add extra stainless washers to increase the counterweight on the pan axis, since I used everything on the side. On top arm I have one large counterweight, two small ones and couple of 2.5g stainless washers. I probably don't need them, but the counter weight gets really close to the tilt servo, and I don't want for it to rub. On the bottom I have the other large cylinder, the two medium ones and four stainless washers. Luckily the MCR is happy with it.

    Sorry, I had problems with attaching photos. My Mac is getting brain dead...
     

    Attached Files:

    #13 Pavel Houda, Mar 3, 2019
    Last edited: Mar 3, 2019
  14. Demetri Zuev

    Demetri Zuev New Member

    Joined:
    Aug 29, 2018
    Messages:
    4
    Likes Received:
    1
    Yesterday I had a small shoot for my actor friend where I used the exact setup you have on you photos (Moment wide + Tiffen pola). I still couldn't achieve the perfect balance as in your pics but motors powered through. I'll keep trying to get the balance right, I mean, if you can get it with the exact same setup so can I :) Thank a lot for such a detailed response!
     
    Pavel Houda likes this.
  15. Pavel Houda

    Pavel Houda Member

    Joined:
    Jan 15, 2019
    Messages:
    59
    Likes Received:
    25
    @Demetri, you are welcome. One thing to keep in mind is that the iPhone Xs Max has the TILT/ROLL pivot point somewhere in the center of the clamp where it says MOVI.

    You are trying to balance the gravity forces at this point. The axes go through the pivot point, tilt axis is horizontal left/right through this point, parallel with the phone, the roll axis is also horizontal, through the middle of the roll servo - perpendicular to the phone. The pan axis goes vertically through the center of the pan servo. You are simply trying to balance the gravity forces around these axes.

    The iPhone Xs Max, unfortunately, has the lenses at one corner, way away from the pivot point, and the way the counterbalance framework is made, it places the lens even farther away from it. Because the phone is asymmetrical weight wise as you add lens/filter, its easier if you add more weight on the lower arm. That way you will not run out of balancing range as easily.

    Keep in mind that the design of the counterbalance system forces an interaction between the tilt and roll.

    When adjusting the roll and the camera rolls towards the lens, you have to move both counterweights towards the horizontal axis (right), to get the center of gravity of the counterweights right. That will generally screw up the roll balance. Easiest is to point the lens down and try to move the upper arm away from the axis if the phone screen leans towards you, or towards the axis if it leans away from you. You can do the same with the lower arm, but with opposite effect - to make the scree to tilt towards you - move the arm away from axis, to tilt away, move the arm towards the axis. These adjustments will certainly screw up the the original roll adjustment, so you may need to move BOTH arms a little to achieve roll balance. You will probably need to go back and forth several times to balance both axes properly. Also make sure that you have roll/tilt balance when pointing down.

    If you can't move the arms right any more, you will need to add weight. Conversely, if the camera rolls with towards the counterweights, spread the arms away from the horizontal tilt axis, to move the center of gravity of the counterweights towards the pivot point. Then rebalance the tilt as described above. If you cannot spread the arms any more, remove some counterweights.

    Couple of other things, tilt adjustment in VERTICAL position of the MCR, move the counterweights away from you, if the screen tilts down towards you and move the counterweight cylinders towards you if the screen tilts up towards the servo. These adjustments will not effect the roll.

    At the end of this, you should be ok with tilt/roll in either horizontal or vertical position of the MCR. The pan should be balanced ok when you have the phone in horizontal position (lens down). Try to move the phone little off horizontal - left or right down a little. If the phone doesn't stay in those positions but continues to roll, you need to add extra weight to the pan arm counterweight. I used fender washers for this, since the the counterweights are either too light or too heavy for this.
     
    #15 Pavel Houda, Mar 5, 2019
    Last edited: Mar 6, 2019
  16. Jerry Tran

    Jerry Tran New Member

    Joined:
    Mar 10, 2019
    Messages:
    4
    Likes Received:
    0
    924FBB25-AA02-4A8A-87F0-18CBE1810D18.jpeg 76986119-E817-4FAD-8EA5-8642904ADB82.jpeg 103F2A0E-733B-4A08-885E-04C65F876DB2.jpeg CCA26B0D-549A-4ECA-BC0F-9A4C6017171C.jpeg
    I also have the MCR with the moment wide filter adapter and a 62 mm ND Variable filter.
    I had no problem achieving perfect balance with the moment wide and the counter balance kit using the large and medium weights top and bottom of the rig and the two small weights on the clamp on weight.
    I did however have no luck once I added the filter adapter and a ND filter to the lense. I just didn’t have eneough weight to counter balance the lens and filter it was just to heavy so I went to Freefly site and ordered the additional weights. It was free shipping and I received them the next day. I added one small weight to the top of the rig and one medium to the bottom. And with just a slight adjustment I was in perfect balance all around.
    So that’s great for the wide lens with and with out the filter.
    The problem now is when I switch to my anamorphic lense everything completely changes again and different weight configurations are needed.
    With all the money I have invested in this already I figure why not spend another $69 for another counter balance rig and have a rig set up and dialed in for each lens.
     
  17. Pavel Houda

    Pavel Houda Member

    Joined:
    Jan 15, 2019
    Messages:
    59
    Likes Received:
    25
    Moved to new thread: "Method of balancing Movi Cinema Robot using variety of Moment lenses with minimum of counterweight Adjustments".
     
    #17 Pavel Houda, Mar 13, 2019
    Last edited: Mar 15, 2019
  18. Jim Heitzman

    Jim Heitzman New Member

    Joined:
    Apr 14, 2019
    Messages:
    4
    Likes Received:
    1
    I had mixed feelings too! I thought I was doing my homework researching before I made my purchase.
    Obviously I didn't because this thread clearly spells it out for me.
    Putting this thing back in the box and off it goes on the way back to Freefly in the morning.
     
  19. Darell Sison

    Darell Sison New Member

    Joined:
    Apr 12, 2019
    Messages:
    29
    Likes Received:
    6
    I however have a different view.

    Managed to balance iPhone XS Max, Moment Case and Anamorphic Lens with standard counterweight set. I didn't even use the medium weights.

    I came from a Zhiyun Smooth 4 and the ergonomics and functionality of my MCR is just above and beyond what a typical gimbal can do.

    Yes the counterweight is a bit of a pain but I think once one gets comfortable with the nudges and adjustments it gets easy.

    My fingers began to hurt adjusting the thumbscrews however, much like a guitarist learning string pain.

    Best of luck everyone!
     
  20. Jim Heitzman

    Jim Heitzman New Member

    Joined:
    Apr 14, 2019
    Messages:
    4
    Likes Received:
    1
    Pain?
    Excruciating pain!

    What I failed to understand was the fact of having to spend $80 more for the expensive ridiculous counterweight accessory because unless you have a small phone and don't have this kit, its a boat anchor. I have a big phone and want to use a filter of some sort, but dang. Also, you cant just grab the handle wrapping your fingers around it, nope. You got to make a weird grip keeping fingers out of the pathway from that ridiculous counterweight that's rotating while youre shooting because one bump and you've ruined your shot. Done. Toast.

    I didn't expect not having the ability to just grab this gimbal, throw it in my bag and go shoot. I either have to set this all up up before I leave the house or do it after get on site (and pray it doesn't get bumped) and spend the necessary 15-20+ mins putting the phone on, adding my filter and tweaking it, balancing it out (again) getting the Movi app turned on, turn on the Filmic Pro app, go into the app Settings, turn on the hardware allowance radio button, THEN start shooting.

    Oh, and pray that I brought the required small Allen wrench (not included) with me if I need to swap out the counterweights, those aren't thumbscrews at the end of them holding them together, Skippy.

    I spent over $430 plus the $30 hoodie thingie to add a mount for a decent mic but you know what?
    NOT.
    I would be adding MORE weight and adding MORE bulk and this thing already feels and weighs like I have a full-on DSLR with a big heavy lens on it when I tote this around, much less what would happen if it left my hands in a stumble hitting the ground or pavement!
    If you're in a shady part of town, you cant just tuck this now- heavy monstrosity away inconspicuously away. It's pretty much out there. BUT it now is a weighty object that you can you can use as a weapon for self defense!
     
    #20 Jim Heitzman, Apr 15, 2019
    Last edited: Apr 15, 2019
    viktor manshtein likes this.

Share This Page